Needle transfer device

ABSTRACT

A needle sorting device includes an infeed device which first singulates a bulk supply of surgical needles into single file with an intermittently driven vibratory feed bowl assembly, and then individually separates and deposits the needles on a first conveyor for transmission to a processing station with a linear slide discharge mechanism. The first conveyor is translucent and during transit, one or more cameras obtain an image of the individual deposited needles. The image is digitized and the digital signals are transmitted to a control system computer which evaluates the position and orientation for needles and processes the information to obtain data for communication to one or more robot assemblies having grippers. Utilizing the position and orientation data, the robot assembly grippers removes selected needles from the first conveyor and transfers each needle to an engagement device located upon a second precision conveyor. This second precision conveyor is provided with additional devices to further orient the needle transferred thereto. A moveable hard stop is provided at the end of the precision conveyor to provide precise positioning of the needle to an accuracy of 0.001 inch at needle hand-off. Each oriented and precisely positioned needle is conveyed by the second conveyor to an automatic swaging station where sutures are automatically attached.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 08/715,790,filed Sep. 19, 1996, now U.S. Pat. No. 5,727,668 which is an FWC of U.S.Ser. No. 08/567,264, filed Dec. 5, 1995, abandoned which is acontinuation of U.S. Ser. No. 08/181,600 filed Jan. 13, 1994, now U.S.Pat. No. 5,511,670, all of which are entitled "Needle Sorting Device".

1. FIELD OF THE INVENTION

The present invention relates generally to machines for automaticallyproducing armed surgical needles, i.e., surgical needles having suturesattached thereto, and more specifically, to an infeed apparatus thatautomatically sorts needles and feeds them for further processing, fore.g., to an automatic swaging device.

2. DESCRIPTION OF THE PRIOR ART

Most armed surgical needles, i.e., needles having sutures attached toone end thereof, that are in present use by surgeons and medicalpersonnel, are manufactured utilizing manual and semi-automatedprocedures such as those described in U.S. Pat. Nos. 3,611,551,3,980,177, and 4,922,904. For instance, as described in U.S. Pat. No.3,611,551, manual intervention is required by an operator to accuratelyposition a suture within the needle for swaging and to adjust swagingdies to increase or decrease swage pressure when suture strands ofdifferent gauges are to be swaged. This process is costly in terms ofman-hour labor and efficiency because manual positioning is required forswaging to take place.

Presently, suture material may be supplied wound on a bobbin, or, a kingor driven spool before being cut and positioned within the swaging endof a surgical needle. In U.S. Pat. No. 3,980,177 the suture material isfed from a spool and taken up on a rotating tension rack where uniformlength strands are subsequently cut. Thus, the length of the suture isdetermined by the size of the rack and manual intervention is requiredto prepare the rack for the cutting of the suture material woundthereabout. Moreover, manual intervention is required to change the rackeach time a suture strand of different length is desired.

In U.S. Pat. No. 4,922,904, the suture material is supplied wound on abobbin and is fed through various guide means and a heater forstraightening the material, prior to insertion within the crimpingcavity of the surgical needle. In one embodiment shown therein, anelaborate television monitoring means is required for aligning the drawnsuture within the crimping cavity of the surgical needle prior toswaging thereof. In the same embodiment, a rotary encoder device is usedto determine the length of suture material unwound from the bobbin priorto cutting. In an alternative embodiment, after swaging of theindefinite length of suture material to the needle, the needle-sutureassembly is fed a predetermined distance prior to cutting to obtain asuture strand of predetermined length. Thus, to obtain uniform lengthsof suture material every time requires careful manipulations and precisecontrols, and the processes used to accomplish these tasks are alsocostly in terms of man-hour labor and efficiency.

U.S. Pat. No. 5,065,237 describes the automatic sorting of mail such asenvelopes using conveyors with black and white stripes, a video camerafor detecting the edge of a mail piece, and a limited function roboticdevice for picking up a mail piece based on the leading edge of themail, but it is not capable of singulating, imaging or sorting surgicalneedles.

U.S. Pat. No. 5,150,307 discloses a computer controlled sortingapparatus for separating and sorting plastic items having a means forconverting an image into digital signals for singulation, but is notcapable of determining orientation of needles, the precise placementthereof, or of picking a needle up for placement in a precisionconveyor.

U.S. Pat. No. 4,651,879 discloses a bottle sorting station having aconveyor, a transfer device and an engagement device for sortingbottles, but does not singulate from bulk, nor is it able to determineorientation of a surgical needle or provide precise placement of theneedle after sorting.

It would be highly desirable to provide an armed needle production andpackaging system that is fully automated and that includes means forautomatically feeding surgical needles to an automatic swaging machinefor the swaging of sutures thereto.

It would also be highly desirable to provide in an armed needleproduction apparatus, a needle sorting device that can efficiently andaccurately orient a needle for subsequent transference to an automaticswaging station.

Even more desirable would be the provision of a control system tomaintain the efficiency and integrity of the needle sorting andtransferring function.

It would be desirable to provide a needle sorting and singulatingapparatus which provides precise pre-positioning of individual needlesbefore imaging to minimize the rejection and recycling of overlappingand nested needles.

It is a further object of the present invention to provide an improvedand moveable precise positioning hard stop which will accurately locatethe butt end of a curved needle within 0.001 of an inch for hand off toan automatic swaging apparatus.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the instant invention to provide anautomatic needle sorting device for singulating and conveying individualneedles to a needle processing location.

It is another object of the instant invention to provide a costeffective needle sorting device that virtually eliminates operatorexposure to repetitive manual operations.

It is another object of the instant invention to provide an automaticneedle sorting device that singulates and positions individual needlesin a precise and predetermined orientation for transfer to an automaticswaging station for attaching armed surgical needles thereto.

These and other objects of the present invention are attained with anapparatus for automatically sorting needles and preparing them forautomatic swaging and packaging in a reduced size organizer. The needlesorting device comprises at least one receptacle means for holding aplurality of needles, the receptacle means being provided with a meansfor singulating the needles into a single file of individual needles,and then depositing individual needles on a first translucent indexingconveyor means to provide a moving line of singulated needles forfurther imaging, manipulation and handling. A first set of remotelylocated video camera means obtains images of the individual needles uponthe first conveyor means and the images are subsequently digitized toenable processing by a control system computer. The digitized signalsare processed to obtain both positional and orientation data forindividual selected needles on the conveyor. In as much as a curvedneedle has a sharp point on one end thereof and a butt end on the otherend thereof for receiving a suture, it is necessary to determine notonly the needles position, but also its orientation.

A robot assembly is provided for transferring individual selected andimaged needles from the first conveyor means to a second precisionconveyance means for conveying the needles to an automatic swagingmachine.

The control system computer additionally generates instructions for useby the robot assembly based upon the positional and orientation data ofthe selected unoriented needle. The robot assembly receives theinstructions from the control system so that a robot arm may grasp eachselected needle and position it in an engagement device located upon thesecond conveyance means.

One or more orientation devices are provided to ensure that the needlesare all uniformly oriented up to within 0.001 of its specified positionupon the second conveyor means, so that a transfer for subsequentswaging can effectively take place.

The needle sorting system may also be provided with a second videocamera means and a second robot assembly means that operate in themanner as described above on a second conveyor. The redundancy isdesigned in the system to ensure that a continuous and uninterruptedflow of about 60 needles/minute is supplied to the automatic swagingstation.

Further benefits and advantages of the invention will become apparentfrom a consideration of the following detailed description given withreference to the accompanying drawings, which specify and show preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the process flow for the needlesorting apparatus of the present invention.

FIG. 2(a) is a diagrammatic view of a reduced size organizer used forpackaging needles and sutures which together with FIG. 2(b) illustratethe range of sizes for surgical needles to be handled by the presentinvention.

FIG. 2(b) is a diagrammatic view of a reduced size organizer used forpackaging needles and sutures which together with FIG. 2(a) illustratethe range of sizes for surgical needles to be handled by the presentinvention.

FIG. 3(a) is a top view of the needle sorting device 20 of the instantinvention illustrating the initial vibratory bowl parts feeders whichsingulate the needles, the linear slide discharge mechanisms, the firstand second translucent indexing conveyors, the robotic assemblies andthe precision conveyor.

FIG. 3(b) is a side elevational view of the needle sorting device ofFIG. 3(a) showing the robot assembly above the first conveyor means andthe vision tracking means comprising two video cameras for obtainingimages of the needles and the control system means for processing theimage data.

FIG. 4(a) is a detailed side elevation view of the linear slidemechanism used to singulate and deposit individual needles onto thetranslucent conveyors.

FIG. 4(b) is a detail cross-sectioned view of the linear slide device ofFIG. 4(a) taken along section line B-B' showing the slide above one ofthe translucent conveyors.

FIG. 4(c) is a detailed plan view of the linear slide mechanismillustrated in FIG. 4(a).

FIG. 4(d) is a detailed top plan view of one of the vibratory conveyorbowls and the needle trackway used to feed the linear slide mechanisms.

FIG. 5 is a top view of the precision conveyor and illustrates theconveyor, the needle plow mechanism, the needle pre-positioningmechanism, the moveable hard stop and the multi-axis gripper. Theconveyor is shown carrying needles that have been positioned thereon.

FIG. 6(a) is a detailed view of the precision conveyor boat having jawsfor engaging and retaining an oriented needle for subsequent swaging.

FIG. 6(b) is a detailed elevation view of the precision conveyor boattaken along line 5--5 of the boat illustrated in FIG. 5(a).

FIG. 6(c) is a detailed view of the precision conveyor boat with movablejaw extended for placement of needle oriented for automatic swaging.

FIG. 7 is a side view of the robot load solenoid that actuates the jawsof the precision conveyor boat.

FIG. 8 is schematic representation of the control and data flow for eachof the control tasks of the needle sorting apparatus of the presentinvention.

FIG. 9(a) is a side view of the needle rollover (plow) which ensuresuniform orientation of the needle on the conveyor boat prior toautomatic swaging.

FIG. 9(b) is a front view of the plow taken along line 9--9 of FIG.9(a).

FIGS. 9(c)-9(e) is a front view illustrating the plow 54 orienting aneedle in one direction upon a boat 40 of the precision conveyor.

FIG. 10(a) is a side view of the needle pre-positioning assembly 95which further orients the needle 19 within the engagement jaws ofconveyor boat 40.

FIG. 10(b) is a top plan view of the needle pre-positioning assembly 95for further orienting the needle 19 within the engagement jaws ofconveyor boat 40.

FIG. 11(a) is a plan view of the moveable hard stop assembly 80 forfinal positioning of the needle 19 in conveyor boat 40.

FIG. 11(b) is a front elevation view of the moveable hard stop assembly80 illustrated in FIG. 11(a).

FIG. 12 is a side view of the face cam plate used by the moveable hardstop assembly 80 to retract the hard stop after transfer of theprecisely positioned needle.

FIG. 13(a) is a top plan view of the hard stop used by the moveable hardstop assembly 80.

FIG. 13(b) is a side elevation view of the hard stop illustrated in FIG.13(b).

FIG. 14 is an elevation view of the multi-axis gripper of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention is drawn to a needle infeed apparatus that is designed toautomatically singulate, convey and align surgical needles of varioussizes to an automatic swaging station where sutures are attached toindividual needles.

FIG. 1 is a block diagram generally illustrating the process 10 used tosort needles prior to automatically swaging sutures thereto and prior topackaging them in a reduced size organizer. The automatic needlethreading and swaging system and the automatic packaging system of theparent application are both described in further detail in respectiveU.S. Pat. Nos. 5,438,746 and 5,473,854 assigned to the same assignee ofthe present invention. As previously mentioned, this invention is drawnto a needle sorting device used to sort, singulate, and convey surgeons'needles of various sizes to an automatic swaging station.

FIGS. 2(a) and (b) diagrammatically illustrate the size range of needlesto be singulated and positioned for swaging by the present invention.Each reduced size organizer package holds a typical surgical needle 19having a barrel portion 83, an arcuate blade portion 87, and a suturereceiving end or opening 85 for swaging a suture thereto.

The RSO package illustrated in FIG. 2(a) is illustrated with an EthiconSH-1 needle 19(a) which is 0.018 in diameter and spans an arc of 0.562inches. The suture to be attached to this needle is 0.0055 to 0.0088 indiameter. The suture opening formed in the barrel of this needle is0.0106 in diameter, which requires an alignment tolerance of+0.001/-0.0005 when inserting the suture into the needle.

The RSO package illustrated in FIG. 2(b) is illustrated with an EthiconCTX needle, which is 0.050 in diameter and spans and arc more than twicethe size of needle 19(b) at 1.3125. The sutures to be attached to thisneedle are 0.0126 to 0.0176 in diameter. The suture opening formed inthe barrel of this needle is 0.0202 in diameter, which requires analignment tolerance of +0.001/-0.0005 when inserting the suture into theneedle.

While the present invention serves the purpose of singulating needlesfrom a bulk manufacturing operation, it also provides a method and meansfor precise positioning of the needle during the hand-off to a precisionmulti-axis gripper than will grip the needle and hold it during sutureinsertion. Thus high precision is necessary in the later stages of thepresent invention, or the sutures can not be automatically inserted intothe needle barrel in the subsequent swage operation.

The packages illustrated in FIGS. 2a,b are primarily intended toillustrate the problems inherent in determining the position andorientation of a wide size range of needles, since an arcuate centergrip point on the curved portion of the needles from varies by more than100% in one dimension, and over a half inch in the other dimension.These variances must be reduced to an accuracy of 0.001 before hand-offof the needle to the swage operation.

In addition to the accuracy of positioning, a correct orientation mustbe determined. To a convention vision systems the needles appear as arcswith similar ends. However, it is vitally important to determine withthe vision system, which end is the barrel end and which end is thesharp end, or the subsequent swage operation will fail.

Generally, in the automatic needle sorting process 10 shown in FIG. 1,needles are first loaded into a vibratory bowl at step 11, automaticallysingulated into single file and individually fed in a spacedrelationship at step 12 to a translucent indexing conveyor. Thetranslucent indexing conveyor allows imaging of the needles 19 at step13, which images are converted to digital data, and evaluated withrespect to orientation and position by a vision tracking system which ispart of a computer control system at step 14. After determining positionand orientation, the needles are picked up by a robot apparatus at step15, and transferred to a precision conveyor by the robot apparatus atstep 16. At the final step the needles are pre-positioned and thenprecisely positioned where they are transferred to a multi-axis indexingmeans for conveyance to subsequent swaging workstation at step 17.

A detailed explanation of the apparatus used to carry out each step willbe explained in further detail hereinbelow. A further explanation of thecomputer control system may be found in U.S. Pat. No. 5,568,593 assignedto the same assignee of the present invention.

The preferred embodiment of the needle sorting and infeed apparatus 20is illustrated in the top view of the system in FIG. 3(a) and the sideview of FIG. 3(b). As shown therein, needles 19 are delivered in bulk toeach of two vibratory bowls or hoppers 21a,b where they are singulatedby the vibratory bowls into a single file of needles, and intermittentlyfed to the linear slide discharge assemblies 22a,b where they areindividually deposited upon each of two translucent conveyors 25a,b. Thetwo translucent conveyors 25a,b carry the singulated and depositedneedles 19 in the direction indicated by the arrow A in FIG. 3(a) wheretheir position and orientation are evaluated by a remotely locatedvision tracking system that will be discussed in detail below withrespect to FIG. 3(b).

The tracking system evaluates the position and orientation of eachavailable needles on the translucent conveyors 25a,b as it forwardlyconveys the needles over illuminated (backlit) platforms 30a and 33b andfurther evaluates the position and orientation of the each availableneedle upon translucent conveyor 25b as it forwardly conveys the needlesover illuminated (backlit) platforms 33a and 33b.

The orientation and positional information obtained from the visiontracking system is processed and converted to coordinates usable by eachof two robot assemblies 50a,b for instructing respective robot grippers55a,b to pick up and transfer identified needles from one of thetranslucent conveyors to individual engagement boats 40, located on aprecision conveyor 35 that is also being indexed in the same directionas the translucent conveyors as shown in FIG. 3(a).

The control system computer instructs a robot gripper, for e.g., gripper55a of the robot assembly 50a, to grab the tracked needle from one ofthe two conveyors 25a,b for a dwell cycle of the system, i.e., when therespective conveyor has paused. If the singulated needles 19 areoriented such that neither of the robot grippers 55a,b are able to pickone of them up or place a needle onto the precision conveyor because ofits limited range of motion, a recovery procedure will be executed toensure that there are no shortages of needles 19 to be fed by theprecision conveyor 35 to the automatic high-speed swaging workstation(not shown) which can achieve up to 60 needle swages per minute.

In the preferred embodiment, the timing of each conveyor 25a,b isidentical, but the dwell periods are out of phase. Because of the phasedtiming, the vision tracking system will be identifying needles on oneindexing conveyor, for e.g., 25a, while both robots are picking needlesfrom the other indexing conveyor 25b and placing each needle in anindividual engagement boat of the precision conveyor. Similarly, whileboth robots are picking needles from the indexing conveyor 25a, thevision tracking system will be identifying needles on the other indexingconveyor 25b.

The first step of the automatic swage/wind process 10 involvesintroducing a predetermined amount of needles 19 from an infeed device,such as a vibratory bowl or hopper, which serves as the first componentin the needle singulating assembly.

This first step in singulating needles for the automatic swage/windprocess 10 involves singulating individual needles from a bulk supply ofneedles for introduction to the vision inspection system. In the deviceillustrated and described in the parent application, U.S. Ser. No.08/567,264 and U.S. Ser. No. 08/181,600, the singulating deviceseparated needles into groups of three for deposit on a moving conveyorwhich needles were then imaged. Some of these needles fell in anoverlapping relationship and when that happened, the vision system wouldautomatically exclude that group of needles and the needles would thenbe recycled back to one of the vibratory bowls for a second singulationstep. This recycling is undesirable inasmuch as it increases the riskthat a needle point may become blunted by contact with other needles, orthat the swage apparatus fed by the present invention may missswage/wind cycles during operation.

The improvement of the present invention therefore includes an improvedvibrating hopper assembly which singulates the needles into a singlefile, and a linear discharge slide mechanism which provides for timedand positioned placement of the needles on the translucent indexingconveyor.

As illustrated in FIG. 3A, a pair of vibrating bowls 21a and 21b areillustrated. In the preferred embodiment, both bowls 21a and 21b areprovided with a singulating track for singulating the needles intosingle file, but only a single track is illustrated in FIG. 3A. A pairof linear slide discharge mechanisms 22a,b are also provided totransport and align individual needles from the vibrating bowls assembly21a,b to the translucent conveyors 25a,b for imaging by the inspectionsystem.

The function of the improved feed mechanism, including a vibrating bowland a linear slide discharge mechanism, is to deposit individual needlesin a spaced relationship on the translucent conveyor 25 for imaging bythe vision system and subsequent handling by the robotic assemblies50a,b.

Two separate needle feed mechanisms are illustrated in FIG. 3(a) to feedtwo separate translucent indexing conveyors. In FIGS. 4(a)-4(c), thelinear slide mechanisms 22a,b are illustrated in greater detail, and thevibrating bowl assembly is illustrated in greater detail in FIG. 4(d).Parts that are substantially identical in the two separate feedmechanisms are identified with the same reference numeral with an (a) or(b) suffix, depending on which feed mechanism they are associated with.When a part is referred to without the suffix, it is understood thedescription applies equally to both needle feed mechanisms.

As illustrated in FIG. 4(d), a vibrating bowl assembly receives aplurality of needles in bulk on a central floor area 121. The vibratingbowl is a modified vibrating parts feed device manufactured by FMC Corp.to provide between 60 and 100 parts per minute. The bowl is fabricatedof surgical stainless steel with a polyurethane lining in the bowl andall riding surfaces of the track assembly are also coated to preventdamage to the needle points. The track assembly 122 is a continuousspiral track which begins at the bottom of the bowl at 122(a) and endsat the linear discharge point 122(b). The track includes along virtuallyall of its entirety a vertical rib 122(c) which supports the needleduring the vibratory transport as illustrated by the needle 123 atposition C. The needles are transported from the floor 121 at position Ato the discharge point 122(b) by pulsed vibration from vibratory unit124 controlled by a control means 125. The vibrations supplied by theunit 124 are both vertical and horizontal and are timed to coincide toprovide a maximum rate of movement for the needles 123. Track member 122begins at the floor of the unit 121 and winds upwardly to the top of thevibrating bowl wherein the vertical portion 122c is interrupted for apair of vertical gates 126 and 127 which redirect overlapping needlesand nested needles back into the vibrating bowl 21. A secondary trackand dam 127 is used to catch overlapping needles screened by the firstdam 126 and return them to the floor of the hopper 21 with minimaldamage to the points of the needle. Each of the vertical dams 126, 127include adjustable knock off screws 126a,b and 127a,b which are used toprovide precise adjustment of dams 126 and 127 for various needle sizes.Thumb screws 126c,d and 127c,d provide coarse adjustment of the gates126,127 while knock off screws 126a,b and 127 a,b provide for fineadjustment thereof.

As stated earlier, the entire raceway track 122 and the vibrating bowl21 are coated in polyurethane to minimize any damage to the needlepoints. The polyurethane coating on the stainless steel bowls and thesilicone coating on the needles tend to create during operation of thedevice a static charge which can effectively inhibit movement of theneedles along trackway 122. This static buildup may be countered in oneof two ways, first by providing a stream of ionized air over thetrackway or second by coating the polyurethane racetrack 122 with aTeflon spray lubricant available commercially. It has been found that anapplication of the Teflon spray lubricant will remain effective forapproximately 500,000 needles.

The pulsed vibration of vibrating unit 124 provides a single file streamof needles oriented on trackway 122 as illustrated at position B and Cby needles 123. As they reach the end of the track 122b, they are firstdetected by an optical sensor 128 which is activated by the reflectionof the needle on the trackway 122. When the needle has fallen from thetrackway at 122(b), a second detector signal is generated by a secondoptical detector 129. The electrical signals from optical detectors 128,129 are provided to control means 125 for use in controlling thevibratory motor 124 as will be hereinafter described in greater detail.

Vibrating bowls 21a,b provide a serial single line output of needles,dispensed one at a time to the needle feed stations 22a,b which are morefully illustrated and described with respect to FIGS. 4(a)-4(c).

As illustrated in FIG. 4c, the needle feed stations include a firstlinear slide 22a and a second linear slide 22b which are reciprocatedbetween the two positions illustrated in FIGS. 4(c) by slides 22a and22b. In a first position, as illustrated by the linear discharge slide22b, a first needle pocket 130 is arranged under the drop point 122b ofthe trackway 122a leading from the vibrating bowl members 121a,b. Aftersensor means 129 has detected a falling needle from the end of trackway122, the linear slide is reciprocated to its second position illustratedby slide 122a in FIG. 4c. In this position, the second needle cup 131ais now positioned below the end of a trackway 122b formed on thevibrator bowl assembly 21a. The pulsing vibrator unit 124 is thenenergized until a second needle is detected by optical sensor 129 as itfalls into needle pocket 131a.

The needle pockets 130 and 131 are formed in a pair of pivoting blocks132,133 which are mounted for pivotal movement on the slide mechanism22a,b. As illustrated in FIG. 4(c), block member 132a pivots on pins134,135 while block member 133 pivots on pins 136, 137.

The pivotal movement is illustrated in FIG. 4(b) wherein block members132, 133 pivot around pivot points 134,136 to the position illustratedat 132(e) and 133(e). As the block members 132,133 pivot, the needlepockets are opened as illustrated in FIG. 4(b) to deposit the needle 123on the translucent indexing conveyor 25. An air slide mechanism 137 andguide rails 138, 139 which provide the reciprocal movement of the slidemechanisms 22a,b are also illustrated in cross-section in FIG. 4(b).

Referring to FIG. 4(c), the block members 132, 133 are pivoted by meansof a second pair of air slides 140a,b which are mounted on a verticalplate 143 which is suspended above translucent conveyors 25a,b by meansof a support base 144. Each of the blocks 132,133 is also equipped withrollers 145, 146 which engage a rectangular raceway 147 when the linearslide mechanism is reciprocated to its forward position as illustratedby slide 22a in FIG. 4(c). When the rollers 145(b),146(b) are receivedwithin rectangular raceway 147(b) the air slide 140b is actuated toraise the rectangular raceway 147(b) vertically. Since block members132, 133 are mounted for pivotal movement with pins 134, 136 on theinbound side of the blocks, a lifting motion on the rollers 145, 146 onthe outbound side of the blocks will cause pivotal movement about pins134,136 as the rollers 145, 146 come together withing the rectangularraceway 147. After the needles have been deposited on the translucentconveyor 25, the air slide 140 is then lowered which returns blockmembers 132, 133 to the position illustrated in FIG. 4(c).

In the sequence of operation, the control means 125 energizes thevibratory motor 124 to vibrate the bowl in a pulsed manner, with theamplitude of the pulses controlled by an adjustable rheostat. Theadjustable amplitude setting varies depending upon the size and mass ofthe needle to be transported along the trackway 122. The needles arethen singulated in single file along the entire length of the track 122from the floor of the vibratory bowl 121 to the discharge point 122b.When optical sensor 128 senses the presence of a needle at the end ofthe trackway, vibrating motor 124 is stopped until the reciprocatingslide 122 is reciprocated to its most rearward position as illustratedin by slide 22b in FIG. 4(c). After linear slide 22b is in position,control means 125 energizes the motor 124 and the needle is vibratedfrom trackway 122 into needle pocket 130b. As the needle falls from thetrackway to the pocket, its presence is detected by optical sensor 129.Control circuit 125 keeps motor 124 vibrating until another needle issensed on track 122 by sensor 128. After receiving a needle, the linearslide 22b is then advanced to the forward position as illustrated byslide 22a in FIG. 4(c). In the event a second needle is detected byoptical detector 128 before slide member 22b has reached its forwardposition, the drive motor 124 is stopped until slide member 22b is inposition to receive the second needle. Thus there are two controlsituations for the deposit of a needle into the second pocket 131b. If aneedle was detected at sensor 128, then the vibrating motor 124 isreenergized to vibrate that needle off the end of track 122 and intoneedle pocket 131b. If a needle has not been detected by optical sensor128, the control means will keep vibrator 124 running following thefirst drop, and the vibrator will continue to run until sensor 129detects a dropping needle. After each drop, the control means 125 keepsthe vibrating motor 124 running until a needle is detected at opticalsensor 128. After both needle pockets 130b, 131b have received a singleneedle, the air slide 141 is actuated opening the needle cups anddepositing the needles therein in a singulated and spaced relationshipon the translucent conveyor 25 for imaging by the optical system andfurther handling by the robotic tracking system.

It should be understood that while the needles 19 deposited ontranslucent conveyor 25a,b are singulated and spaced apart, they will berandomly positioned and unoriented. In the preferred embodiment, eachtranslucent conveyor 25a,b is an endless loop conveyor that is driven ata rate of four inches per sec (4 in./sec) and runs parallel to aprecision conveyor 35 as shown in FIGS. 3(a).

As described above, and in view of FIG. 3(a), the robot assemblycomprises two robots 50a,b located downstream from each needlesingulating assembly 22a,b and proximate both the precision andtranslucent indexing conveyors. In the preferred embodiment describedherein, each robot assembly 50a,b is an Adept® 604-S robot capable ofaccomplishing needle transfers at a rate of approximately 40 transfersper minute as controlled by each robot's corresponding Adept® CCcontroller. Each robot is a four-axis SCARA (Selective ComplianceAssembly Robot Arm) robot comprising four Joints: Joint 1, being theshoulder joint having a rotational range of motion of ±100°; Joint 2,the elbow joint, having a rotational range of motion of ±140°; Joint 3providing translational motion for a robot quill for up to 150 mm in anup down motion; and, Joint 4, being the wrist joint, providing ±360°rotational motion of the quill. Robot grippers 55a,b are attached to thequill of each respective robot assembly 50a,b and are enabled to providegripping action by pressure supplied from an air cylinder (not shown).

Referring now to FIG. 3(b), there is illustrated the precision conveyor35 which is driven by drive motor assembly 42 at a rate sufficient toindex and transfer one oriented surgical needle per second (1needle/sec) to the automatic swaging machine. A similar drive motorassembly 43 is provided for driving the indexing conveyors 25a,b. Aswill be explained in detail below, each drive motor assembly 42,43 isinterfaced with and operates under the control of the control system 69to pause the indexing motion to enable the pick-up and transfer of aneedle from the indexing conveyor to the precision conveyor.

FIG. 5 illustrates in detail the precision conveyor 35 and the pluralityof engagement boats 40 located thereon for engaging respectiveindividual surgical needles 19. Motion of the precision conveyor 35 isalso paused periodically at the desired cycle rate to allow for thetransfer of the needles 19 thereto from the robots 50a,b. The precisionconveyor receives needles 19 with rough positioning from the roboticassemblies 50a,b, in boats 40 as will hereinafter be described ingreater detail with respect to FIGS. 6(a)-(c) and 7. The needles whenreceived in boats 40 are orientated as to point and butt end, but notorientated with respect to the direction of curvature of the needles. Asfurther described with respect to FIGS. 9(a)-(e), a needle plowmechanism 57 is provided to orient the curvature of the needles. Aneedle pre-positioner 95 is also provided to provide prepositioning ofthe butt end of each needle as will be hereinafter described withrespect to FIGS. 10(a) and 10(b). The needles are finally preciselypositioned by the moveable hard stop mechanism 80 and will described ingreater detail in FIGS. 11(a) and 11(b). The individual needles are thenremoved and held for swaging to a suture by a multi-axis gripper 18,which gripper is described in greater detail in FIGS. 14(a)-(c).

In the preferred embodiment, the control system 69 includes aprogrammable logic controller (PLC) that is in digital communicationwith the Adept® robot controllers and the vision tracking systemcomponents to control the infeed system.

As shown in FIG. 3(b), the vision tracking system comprises a cameraassembly 60 having two video cameras 62 and 64, one located overheadeach respective illuminated platform portion, 30a and 30b, for itsindexing conveyor 25a. As will be explained in detail below, the videoimages of the needles obtained from each camera 62,64 are bit-mapped orsuitably digitized and transmitted via suitable transmission media, suchas communication lines 67a,b shown in FIG. 3(b), to the remotely locatedcontrol system computer 69 where a Vision Control task processes thevideo images and inputs the data to each robot 50a,b via communicationline 197. Preferably, the conveyors 25a and 25b are translucent and arebacklit at the respective portions 30a,b and 33a,b so that a sharp videoimage may be obtained by the overhead camera assembly for processing.

It is understood that for descriptive purposes, only two video cameras62,64 corresponding to the two illuminated platforms 30a, 30b are shownin FIG. 3(b). However, the invention includes a second set of videocameras (not shown) corresponding to illuminated platforms 33a and 33bfor conveyor 25b so that, as mentioned above, binary images of needleson conveyor 25b may be obtained while the robots are picking and placingneedles from conveyor 25a. The redundancy designed into this systemensures that there will be no momentary shortage of needles fed to theswaging station and that maximum throughput of oriented needles forinput to the swaging station is achieved.

In the event the state of robotics technology improves, and as the robotassemblies achieve greater degrees of movement at faster speeds, thesecond set of cameras and a second robot assembly may no longer berequired. Furthermore, a robotic assembly of sufficient speed andprecision may be able to pick up randomly deposited needles from amoving conveyor and place them directly in an oriented position at theswaging station.

In the preferred embodiment, each camera 62,64 is mounted approximatelyone (1) meter above each backlit indexing conveyor 25a,b and utilizes anelectrically controlled telephoto lens with a focal distance rangingfrom 10 mm to 140 mm that may be changed with suitable adaptors.Suitable lens controllers are used to establish lighting/iris, focus,and field of view for each camera lens, and, are interfaced with theAdept® controller via an RS-232 link.

A further component of the control system for the needle sorting andinfeed apparatus includes an SCADA Node which is used to oversee anddirect the infeed system. This node interfaces with each of the Adept®controllers via discrete RS-232 links which are used to download datainformation, such as needle parameters, error messages, and statusmessages, to the Adept® controllers during run-time. The SCADA node maycomprise a personal computer or such suitable device, runningcommercially available FIXDMACS® software. Serial communication is usedto exchange the needle parameters entered at the FIX/DMACS "Adept®Setup" screen during a needle changeover procedure which is used toinform the infeed system of the size and type of needles to beprocessed. After an operator enters the needle parameters and initiatesa changeover, the FIX/DMACS Node will transmit these parameters to therobot controller(s).

The robotic/vision control system 69 of the invention comprisesindividual computer software programs, each associated with a particulartask to be performed by the needle sorting and infeed system 10 andexecuted under the control of the PLC 120. As shown in FIG. 8, thesoftware architecture for controlling the needle sorting apparatus ofthe instant invention performs eight (8) main tasks: a Robot Controltask 150; a Vision Control task 160; a Conveyor Indexing Control task180; a SCADA Node Interface task 195; A Control Panel task 260; a TaskManager 240; a Conveyor Initiation task 190; and, a Lens Control task270. Of these eight tasks mentioned above, the first six are activeduring the needle infeed steady state operation as will be explainedbelow. FIG. 8 additionally shows the data flow among the tasks and thesignals which initiate the tasks. It is understood that the softwarelanguage used in the preferred embodiment, is Adept's V/V+ language,which supports both vision and robotic control in a multitaskingenvironment. Each of the tasks will be generally described below withrespect to FIG. 8. A more detailed description of the following taskscan be found in the above-mentioned U.S. Pat. No. 5,568,593.

It should be understood to those skilled in the art that each robotassembly, controllers, and camera vision tracking system requirescareful calibration and configuration procedures for the infeed systemto properly function. For instance, each robot assembly requires thatjoint positions be set and joint limits be configured to ensure that therobots avoid structural damage when enabled. Furthermore, acamera-to-robot calibration is required so that the vision system mayaccurately compute the positional coordinates of the needle so that therobot may move to the pick position. This procedure provides atranslation matrix between the camera's field-of-view and each robotbase position.

The PLC 120 is responsible for initially powering the robot controllersand robots. A robot calibration procedure may be initiated afterpower-up to move the robot joints to known "home" positions tosynchronize the digital encoders (not shown).

The process of starting the PLC 120, robot controllers, and conveyors25a,b and 35 is time-critical. From the robot controller perspective,when a ROBOT ENABLE signal 219 is raised by PLC 120, it begins itsnormal cycle by executing the Robot Control Task 150, the Vision ControlTask 160, the Conveyor Indexing Control Task 180, and the ConveyorInitiation Task 190; which initiates the movement of conveyor 25a, waitsapproximately up to two (2) seconds, and then initiates the movement ofsecond conveyor 25b as will be described in detail below. The PLCsimultaneously raises the ROBOT ENABLE signal on the other Adept robot.Under this scenario, the PLC integrates the startup of the Bulk FeedingDevice System, the Indexing Conveyors, and swaging machine with theraising of the ROBOT ENABLE signal 219. As will be explained in furtherdetail below, when the ROBOT ENABLE signal goes low, the Adept robothalts its standard processing and responds to requests from the SCADAnode.

Robot Control Task

There is a single Robot Control task associated with each Adept®controller for each robot assembly 50a,b although only one is indicatedas element 150 in FIG. 8. The control system software for the RobotControl task 150 manages the respective robot assembly 50a or 50b as aresource, reads a FIFO buffer 155 of identified needle locations whichare produced by and input from the Vision Control Task 160, interfaceswith the programmable logic controller (PLC) 120 of control system 69for needle placement handshaking, and, initiates the indexing of theconveyor belts 25a,b.

The steady state operation of the Robot Control task 150 for each robotassembly 50a, (50b) is as follows:

First, the respective robot controller continuously polls its input FIFO155 via data line 193 to obtain positional coordinate data for theidentified needle locations on a respective translucent conveyor 25a or25b. The data for the needle locations are provided to the FIFO bufferfrom the Vision Control task 160 via respective data lines 197 as willbe explained in further detail below. When an acceptable (recognizable)needle position is entered into the FIFO buffer 155, the robotcontroller will remove the needle position from the buffer and directthe robot gripper arm 55a,(55b) to move to that location on the conveyorbelt. Next, for each recognized needle, the Robot Control task 150 willsignal the robot gripper 55a,(55b) to close on the needle barrel portion7 and to depart from the conveyor to an approach location proximate theprecision conveyor 35. The robot control task then generates a NEEDLE INGRIPPER signal 207 to the PLC as indicated and waits for a response fromthe PLC 120. As shown in FIG. 8, when the PLC receives a Robot taskgenerated NEEDLE IN GRIPPER signal 207, the PLC 120 will generate a SAFETO PLACE signal 191 for receipt by each of the robots 50a,b. The purposeof the SAFE TO PLACE signal 191 is to inform the respective robotassembly 50a,b that a needle may be placed onto a precision conveyorboat 40 of conveyor 35. As a response to the receipt of the SAFE TOPLACE signal 191, the Robot Control task 150 will generate a DON'T INDEXPRECISION CONVEYOR signal 204 for receipt by the PLC 120 immediatelybefore it places the needle on the precision conveyor 35. While thissignal remains high, for e.g., at a logic "1" state, the Adept® robot50a or 50b will attempt to place a needle onto a boat 40 of precisionconveyor 35. This involves initiating the engagement jaws 47,49 of theprecision conveyor engagement boat 40 to retract to allow the placementof the needle therebetween, as will be explained below. Once themovement of the robot has settled and a needle is placed, the Robot task150 will generate a NEEDLE PLACE COMPLETE signal 206 for receipt by thePLC 120 and, the PLC will generate a suitable control signal 209 toenable the engagement jaws of the precision conveyor engagement boat 40to engage the needle. In the preferred embodiment, the dwell time of theNEEDLE PLACE COMPLETE signal 206 is approximately 48-64 milliseconds.After activating this signal, the robot assembly 50a,b will hold theneedle in place for the same time period. (48-64 msec.) Immediatelythereafter, the robot will open its grippers and move back to itsapproach location away from the engagement boat 40. Finally, the DON'TINDEX PRECISION CONVEYOR signal 204 is removed indicating that it is nowclear for the precision conveyor 35 to index which is performed at thecommand of the PLC 120.

As a safety interlock for conveyor index initiation, the Robot ControlTask 150 will signal the Conveyor Indexing Control Task 180 with aninternal control respective LAST PICK signal 192, 196 indicating thatthe robot assembly, 50a or 50b, has picked up the last needle from thecurrent conveyor as indicated in FIG. 8. If the maximum number ofneedles expected per current camera field-of-view (hereinafter "FOV") isnot picked from the respective current infeed conveyor belt 25a,(b), theRobot Control Task 150 will request the Conveyor Control task 180 toindex that conveyor belt "early" via the INDEX CONVEYOR 1 EARLY or theINDEX CONVEYOR 2 EARLY signals 211,212 as shown in FIG. 8. Since allsignals affecting the motion of the conveyors are routed through theConveyor Control task 180, this task will generate a corresponding INDEXCONVEYOR 1 EARLY, signal 211' INDEX CONVEYOR 2 EARLY, signal 212', forreceipt by the other adept robot. If during normal operation a RobotControl Task receives either Index Conveyor 1 Early or the IndexConveyor 2 Early signal, it will flush the contents of its FIFO buffer155 and continue as if the last needle has been picked from theconveyor.

The control software must take into account the floating 16-32 msduration of a digital output based on the time slicing of V/V+. Thiswill affect the calculation for minimum time required for placement inconjunction with setting and resetting the Don't Index Precisionconveyor signal 204.

The Robot Control Task 150 performs error recovery on two type oferrors. These errors are grouped as indexing errors and gross errors. Asin all other tasks, gross errors cause the Task Manager 240 errorrecovery to respond and stop the Robot Control Task immediately. Anindexing error occurs if a robot is waiting for a needle to be placed inits parts FIFO and both conveyor belts have not indexed within anappropriate amount of time. The Robot Control Task 150 recovers fromthis type of error by requesting the other robot to index early viasignals INDEX CONVEYOR 1 EARLY and INDEX CONVEYOR 2 EARLY signals211,212 respectively. This forces both vision/robot control systems toflush the contents of its current parts FIFO and index the conveyorbelts.

Conveyor Indexing Control Task

The Conveyor Indexing Control Task 180 initiates the indexing of eachrespective translucent indexing conveyor 25a,b and the task is initiatedby the Conveyor Initiation task 190. All signals affecting the motion ofthe conveyors are routed through the Conveyor Control task 180.

As shown in FIG. 8, the first step of the Conveyor Indexing Control task180 is to check for the LAST PICK signal 192,196 internally generatedfrom the Robot Control Task 150 and indicating that the last needlepick-up from the respective infeed translucent conveyor 25a,25b has beencompleted by one of the Adept® robots 50a,b. Alternatively, the ConveyorIndexing Control task 180 awaits for the INDEX CONVEYOR EARLY (1 and 2)signals 231,232 internally generated from the Vision Control task 160when no needles are recognized in the current camera FOV. As a result ofreceiving the LAST PICK signals 192,196 from the robot task, theConveyor Control task will generate a corresponding INDEX CONVEYOR 1signal 198, or, an INDEX CONVEYOR 2 signal 199, for receipt by the PLC120. It is understood that each Adept® robot controller must request thePLC 120 to index a translucent indexing conveyor 25a(,b) after pickingup the last needle from the respective conveyor. Therefor, the otherAdept® robot must generate its corresponding INDEX CONVEYOR 1 (or INDEXCONVEYOR 2) signal for receipt by the PLC before it can command thecurrent translucent conveyor 25a,(25b) to index. As a result ofreceiving the INDEX CONVEYOR 1 EARLY, signal 211' or INDEX CONVEYOR 2EARLY, signal 213' from the Conveyor Control task 180 indicating thatthe maximum number of needles have not been picked up or that there areno or insufficient needles in the respective camera's FOV, the otherAdept robot will generate a corresponding CONVEYOR 1 INDEXED EARLYsignal 198', or CONVEYOR 2 INDEXED EARLY signal 199' for receipt by theConveyor Control task 180, as shown in FIG. 8. These signals will causethe corresponding conveyor 25a(,b) to abort processing and initiateindexing of the belt.

After receipt of both INDEX CONVEYOR 1 or INDEX CONVEYOR 2 signals198,199 from each of the robot assemblies, the PLC 120 commands thetranslucent indexing conveyor 25a to index and generates a correspondingCONVEYOR 1 SETTLED signal 241 or, a CONVEYOR 2 SETTLED signal 242 forreceipt by the Conveyor Control Task 180. Note that the CONVEYOR 1SETTLED signal 241 and the CONVEYOR 2 SETTLED signal 242 are raisedapproximately 2 seconds after the PLC has been requested by the robotcontrol task 150 to index conveyor 25a, (25b). The Conveyor Control Task180 then informs the Vision Control task 160 to begin needle imagingupon receipt of internal control signals 241',242' that correspond tothe respective CONVEYOR 1 SETTLED and the CONVEYOR 2 SETTLED signals241,242. Once the indexing conveyor 25a (25b) has been indexed and thecorresponding CONVEYOR SETTLED signal 241,242 has been received, theVision Control Task 160 may begin needle recognition in thecorresponding cameras's FOV. Specifically, as will be explained below,the cameras 62,64 above conveyor 25a,b each take a snapshot of therespective field of views at respective illuminated portions 30a,b ofthe translucent conveyor and the Vision Control task 160 will controlthe processing of the image to make a determination of whether arecognizable needle is present each camera's field of view.

At this point, a distinction must be made between the mere presence ordetection of a needle in the field of view and the presence of a"recognizable" needle. A needle may be present, but, for a variety ofreasons, the Vision Task 160 may not be able to determine its positionalcoordinates until the camera vision parameters are changed by theexecution of an auto-imaging algorithm which automatically adjusts theiris and vision system lighting parameters of each camera so that thecameras may subsequently obtain enhanced images that may be processed.During steady state, when the vision task has already "recognized" aneedle in its respective field of view, the auto-imaging algorithm isnot repeated.

Details of the auto-imaging algorithm will be explained in detail below.

Vision Control Task

The Vision Control Task 160 controls and processes the images taken byeach of the two camera assemblies 62,64. Since the timing of the twotranslucent conveyors are phased, only one camera is operating at onetime.

Specifically, as shown in FIG. 3(b), the Vision Control task 160interfaces with each respective camera 62,64 to identify the needlelocations of recognizable needles in that camera lens's respective fieldof view encompassing an area located at respective illuminated platforms30a,30b. The Vision Task 160 then processes the positional andorientation information of the identified needle locations and writesthose locations to the Robot Task FIFO 155 via data lines 197. Asmentioned above, the Vision Control task is additionally responsible forinitiating an early conveyor index if no needles were imaged in a camerafield of view.

As described briefly above, the Vision Control task runs each timeeither conveyor 25a,25b completes indexing. It is initiated to beginneedle recognition upon receipt of either a CONVEYOR 1 SETTLED signal241' or CONVEYOR 2 SETTLED signal 242' which is generated by the PLC 120and routed through the Conveyor Control task 180 each time respectivetranslucent indexing conveyor 25a,25b has ceased indexing, as commandedby the Adept®. Each CONVEYOR SETTLED signal 241,242 goes high (logic"1") approximately two (2) seconds after the PLC has been requested bythe Adept® robot to index a translucent indexing conveyor. Each of theCONVEYOR SETTLED signals 1 and 2 (241,242) remain high until the PLC 120receives the next respective INDEX CONVEYOR 1 or 2 signal 198,199 fromthe Adept robots.

The Vision Task 160 activates that camera which is associated with theconveyor settled signal. When activated, the camera 62,64 takes apicture of the backlit areas 30a,b of the conveyor belt 25a,(25b). Anyimage obtained is preferably converted to binary image data forsubsequent digital processing. The Vision Control task 160 utilizes"vision tools" to detect acceptable needles, and places the coordinatesof acceptable needle pick-up points in the FIFO buffer 155 for the Robottask. An "acceptable" needle in the backlit areas is a needle thatmeasures within the tolerances of the needle parameters that have beenpreviously accepted during the needle changeover procedure. The needlechangeover procedure is a procedure to inform the infeed system softwareof the type and size of the needles in the current batch to be processedand must be executed before making needle batch changes as to bediscussed below. Specified needle tolerances are for the needle radius,barrel width, angular characteristics of the needle with respect to therobots, and the calculated area as computed from the needle parameters.

Auto-Imaging Algorithm

As mentioned above, if a detected needle is unrecognizable, theauto-imaging algorithm is invoked to change the camera visionparameters. Thus, after the binary image data is processed, adetermination is made as to whether the needle image is of the specifiedradius, whether the needle image is of the specified barrel width,whether the needle image has the specified angular characteristics, and,whether the needle image area is within the specified tolerance. If anyof these criteria are out of specification, then an auto-imagingalgorithm is executed which functions to take a series of pictures ofthe same needle image at the respective camera's field of view tothereby enhance the needle image for better needle recognition byimproving the vision parameters between pictures. Thus, after each ofthe series of pictures is taken, the auto-imaging algorithm willautomatically adjust the camera's iris and vision system lightingparameters to enable the vision system to image the needles properlywithin the camera's field of view. For example, when adjusting thelighting of the fields of view, certain camera vision parameters such asthe gain, offset, and binary threshold may be modified. The auto-imagingalgorithm is executed until a needle is recognized in each camera'sfield of view and is not repeated until a needle changeover is executed.

Even when the cameras of the Vision Control task 160 are adjusted,needle images may still not be imaged properly. This is because eachcamera's field of view utilizes a backlighting source and needles thatoverlap, touch with each other, or, are clipped by field of view edgeboundaries will not be considered for recognition. Thus, the VisionControl task will make a determination of whether the needles overlap ortouch each other, and, will determine whether the needles are too closeto the edge of the field of view.

After all of the possible needles are recognized, the Vision Controltask will calculate the needle pick-up coordinates of the acceptableneedles and place them in the Robot Control task FIFO buffer 155 toenable the robot to pick and place the acceptable needle onto theprecision conveyor. In the preferred embodiment, the maximum number ofneedles that can be recognized during each dwell cycle of eachtranslucent indexing conveyor is three (3). If less than this maximum orif no needles are recognized, a robot may be signaled to index thecorresponding conveyor early, causing the vision system to abort itsprocessing as described above.

Vision Task 160 is responsible for limiting the number of needlelocations written to the FIFO to three, since the Robot Control Taskwill pick and place a needle for every needle location passed to theFIFO 155. In the preferred embodiment, the Vision Task is limited tooperate for five seconds per indexing conveyor cycle.

The Vision Control Task 160 performs error recovery on three types oferrors. These errors are grouped as imaging errors, processing errors,and gross errors. The gross errors cause the Task Manager error recoveryto respond and stops the Vision Control Task 160 immediately. When animaging error occurs, the Vision Control Task 160 suspends all executionon the current FOV and requests an early index of the conveyor belt bygenerating either INDEX CONVEYOR 1 EARLY or INDEX CONVEYOR 2 EARLYsignals 231,233 as discussed above. Receipt of these signals causes noneedles to be placed in the parts FIFO and forces both vision/robotsystems to pass on the current FOV of needles. If a processing erroroccurs, the Vision Control Task suspends all processing on the currentneedle and begins processing a new needle in the same FOV if anotherneedle is available. As a result, the Vision Task does not insert theneedle into the parts FIFO.

Conveyor Initiation Task

The Conveyor Initiation Task 190 functions to initiate the ConveyorIndexing Control task 180 and is started whenever the ROBOT ENABLEsignal 219 is raised from the PLC 120. Once started, this task requestsan INDEX INFEED CONVEYOR 1 (25a), signal 237, then waits approximatelytwo (2) seconds, and requests an INDEX INFEED CONVEYOR 2 (25b), signal239, as shown in FIG. 7. The task 190 is then terminated and is notrestarted again until the ROBOT ENABLE signal 219 is lowered and raisedagain.

Task Manager

The Task Manager 240 initializes the software and hardware I/O signals,the global variables, and the vision/robot system tasks. Once thevision/robot system tasks are running, the task manager monitors theintegrity and status of each task currently running and the resourcesthat are controlled by these tasks. The status poll signals 247a-247fare indicated in FIG. 8. The resources are the robot, communicationports, and the I/O signal lines. The Task Manager reports any errors tothe PLC, via the SYSTEM FAIL signal 222, and the SCADA node, via theSCADA Node Interface Task 195. The SYSTEM FAIL signal 222 is generatedwhenever a robot (as detected by the Task Manager) has recognized agross error which prevents it from continuing operation. This signal isactive-low and remains low until the Adept robot is reset. Thus, the PLCmust lower the ROBOT ENABLE signal 219 immediately upon receiving thissignal.

For gross errors occurring with the vision/robot control software, theTask Manager 240 is utilized to detect and recover from these errors bycontinuously polling the status and integrity of all steady-state tasksand resources during program execution. If it is determined that a grosserror has occurred, the SYSTEM FAIL signal 222 will be raised to the PLC120 and all tasks except the SCADA Node Interface Task, the ControlPanel Task and the Task Manager will be stopped. A code indicating thereason for the last unrecoverable error will be available to the SCADANode through the SCADA Node Interface Task. In some cases, an errormessage will be displayed in the Monitor Window of the Adept robotcontroller. After the SYSTEM FAIL signal is raised, the Task Managerwill attempt to correct any problems detected on the robot and notifythe operator through the Monitor Window. In most cases, the operatorwill only need to raise the ROBOT ENABLE signal again to re-set thevision/robot control software.

Control Panel Task

The Control Panel Task 260 presents a mouse controlled panel that allowsan operator to access various software "debugging" utilities, to accessdiagnostics utilities, to control the speed of the robot, and to selectnew positions that the robot will move to for picking and placingneedles. Also, the Control Panel Task allows the operator to stop thevision/robot system tasks from executing.

SCADA Node Interface Task

The SCADA Node Interface task 195 polls the SCADA Node RS-232 interfacefor messages from the SCADA node. The task will act as slave to SCADANode requests for Adept and camera set-up procedures necessitated byproduct changeovers. These requests are valid only when the ROBOT ENABLEsignal 219 is deactivated.

Lens Control Task

The Lens Control Task 270 is initiated only when the SCADA node requestsa new product to be introduced to the vision system and is executed onlyas an off-line process. The Lens Control Task 270 accepts the new needleparameters and adjusts the field-of-view size for both cameras toaccommodate the new product size. The zoom, focus, and iris lenses areaffected by this product introduction, as well as internal vision systemparameters, such as gain, binary threshold, and offset, used forimaging. Once the cameras are adjusted, the task is suspended untilanother new product is introduced to the vision/robot system.

Product Changeover

Prior to enabling the robots to begin the needle infeed process, aNeedle Changeover procedure is invoked to inform the Vision and RobotControl tasks of the control system software of the type and size of theneedles to be processed. This needle changeover procedure must becompleted before making needle batch changes. If a changeover is notcompleted before the first needle batch run after power-up, an errormessage will be displayed at the FIX/DMACS (SCADA Node) screen when therobots are enabled and the robots will not run. If a changeover is notcompleted between different needle batch runs, the vision tasks will notidentify any needle being run.

Essentially, an operator of the system enters the needle parameters inappropriate units, e.g., millimeters and degrees at the FIX/DMACS screenof the SCADA task 195 through data lines 229. Such needle parameters foruse by the Vision tasks include, the needle radius and the radiustolerance, acceptable needle angles and their tolerances, and, theneedle width and the width tolerance.

In addition to inputting needle change parameters for the vision tasks,initial camera set-up parameters associated with the particular batch ofneedles to be processed are also input through the SCADA Node for use bythe system. The software utilizes the information provided by the uservia the SCADA Node to automatically adjust the lens for the correctfield-of-view size, focus, and zoom parameters prior to enabling therobots.

The Precision Conveyor

FIGS. 6(a)-6(c) illustrate the precision conveyor boat 40 to which eachneedle 19 is transferred. Each boat is preferably provided with a pairof jaws; one jaw 47 being fixedly mounted, and the second jaw 49 beingslidable within pocket 42. In operation, a push rod 46 is pressed in thedirection of the arrow "A" shown in FIG. 6(c) to compress spring 52which retracts the position of the movable jaw 49 in the directionindicated by the arrow "B" to allow for placement of needle 19 withinthe notch 44 of both jaws. Normally, spring 52 is biased as shown inFIG. 6(b) to maintain movable jaw 49 in its engaged position forretaining a needle 19 in the notch 44. It should be understood that anytype of releasable engaging mechanism may be provided for releasablyretaining a needle 19 on conveyor boat 40, provided that each needle becorrectly oriented on its respective boat for subsequent swaging to takeplace.

FIG. 7 illustrates a robot load solenoid mechanism 70 that is activatedby signal line 209 from the PLC 120 each time a needle 19 is beingtransferred to a precision conveyor boat 40 as described above. Therobot load solenoid 70 may be mounted to the precision conveyor by anappropriate mounting plate 72. A sensor mounted on the precisionconveyor, is provided to sense the proximity of the precision conveyorboat 40. At such time a conveyor boat is dwelled for transference of aneedle 19 thereto, a release arm 56 of the robot load solenoid isactuated by solenoid 70 to pivot about pin 51 to depress push rod 46 andretract the movable jaw 49 to the position illustrated in FIG. 6(c). Therobot arm 51 then positions the needle 19 between the jaws 47,49 ofconveyor boat 40 for engagement thereof. The release arm 56 is thenretracted by spring 78 as the conveyor boat 40 resumes movement.

For automatic swaging to take place at the swaging station it isnecessary that the needle be precisely positioned within the notch 44 ofengagement jaws 47,49 of the boat 40. This is because the multi-axisgripper generally indicated at step 17 in the system flow chart of FIG.1, must receive a precisely positioned needle for a suture (not shown)to be placed within the suture receiving end 85 of needle 19. To ensurethat each needle is uniformly oriented for transference to themulti-axis gripper of the automatic swaging station, a needleorientation device ("plow") 54 is provided as shown in FIGS. 5(b) and9(a) to orient each needle while engaged between jaws 47,49 on conveyorboat 40. The plow comprises an elongated arcuate blade 57 protrudingfrom a mounting bracket 58 as best shown in FIGS. 9(a) and 9(b). In thepreferred embodiment shown in FIG. 5(b) and FIG. 9(c), the plow isfixedly mounted at one end 48 of the precision conveyor 35 to enablearcuate blade 57 to scoop needle 19 positioned on the conveyor boat 40while in forward motion. After contact is made, the arcuate portion 87of the needle 19 is lifted and rolls over the arcuate blade 57 of theplow 54 as shown in FIGS. 9(c) through 9(e). Provision of the plow 54ensures that each needle conveyed to the suture swaging station isoriented in the same direction.

Another mechanism is provided for further orienting the needle upon theprecision conveyor boat is the needle pre-positioning assembly 95illustrated in FIGS. 10(a) and 10(b). The pre-positioning assembly 95comprises a pulley 99 operable by a drive motor (not shown) and timingbelt 97 for rotating a cam 98 as shown in FIG. 10(a). Cam follower 91 isprovided for actuating arm 93 to reciprocate from a first position abovethe engagement jaws 47,49 of conveyor boat 40, to a position thatenables blade 94 of arm 93 to bear upon the end 85 of needle 19 whilethe precision conveyor boat 40 is conveyed in the forward direction asindicated by the arrow in FIG. 10(b). Impeding the forward motion of theneedle 19 by blade 94 forces the needle to move within engagement jaws47,49 of the conveyor boat 40 so that the engagement jaws 47,49 engagethe needle at a precise location, for e.g., its barrel portion 83. Notethat the cam 98, as driven by timing belt 97, is designed so that thearm stop 93 reciprocates in a timed relation with the forward motion ofthe boat 40 as dictated by the Robot Control tasks 150 and PLC 120, sothat each needle in each conveyor boat 40 is further pre-positioned andoriented. After the needle is oriented, the arm stop 93 is reciprocatedto its position above the conveyor boat 40 to await the next needle forfurther orientation in the manner heretofore described.

Moveable Hard Stop Assembly

After the needle 19 has been prepositioned in the conveyor boat 40 aspreviously described with respect to FIGS. 10a,10b, it is conveyed to anautomatic swaging system (not shown) where a suture is inserted into theneedle, and the needle swaged about the suture. A moveable hard stopassembly 80 is illustrated in FIGS. 11(a) and 11(b) where FIG. 11(a) isa top or plan view of the apparatus and FIG. 11(b) is an elevation endview of the apparatus. The hard stop assembly illustrated in FIGS. 11aand 11b is the mechanism used for executing a hard stop of the needleconveyed in conveyor boat 40 when the boat has reached the end of itsdestination at the hand-off point for the needle swaging station. Thestop 82 (illustrated in FIGS. 13(a) and 13(b) provides a precisepositioning surface for the needle in boat 40. Typically, the hard stop80 provides positioning within an accuracy of 0.001 inches of a denotedreference position subsequently used for swaging. The hard stop of thepresent invention differs from the stop 80 described with respect to theparent application inasmuch as the stop 80 in the parent application wasa fixed stop mechanism whereas the apparatus illustrated in FIGS. 11aand 11b is a moveable stop mechanism. The moveable stop 80 isreciprocated out of the way to provide clearance for the conveyor boat40 as it continues its downward travel to return to the opposite end ofthe conveyor. As the conveyor boat 40 reaches its final position asillustrated in FIG. 11(a) the hard stop 80 is positioned to receive thebutt end of the needle on needle face 80a as illustrated in FIG. 13. Asthe boat 40 arrives at its final location, the gripping jaws of theswage device arrive on the opposite side of the needle hard stop 80. Theneedle is thus restrained during handoff against downward movement bythe hard stop 80, from side-to-side movement by the jaws 47, 49 of theconveyor boat 40 against rearward motion by the conveyor boat 40 andagainst forward motion by the multi-axis gripper on the swage machinewhich is to receive the needle. The multi-axis gripper also has a pairof jaws (not shown) which engage the needle to prevent side-to-sidemotion after transfer is complete, and the jaws 47, 49 are open and thejaws of the multi-axis gripper are closed, the hard stop 80 isreciprocated in the direction of the arrow A in FIG. 11a to provideclearance for movement of jaws 47,49 on boat 40 and for movement of thebutt end of the needle as it is moved out of position by the multi-axisgripper. To provide further clearance for the butt end of the needle,and to avoid dislodging it from its precise position, the trailing faceof the hard stop 80 is tapered as illustrated at 80b in FIG. 13(b).

The hard stop 80 is spring mounted in a pivot arm 150 by means of apivot pin 151 and a coil spring 152 which maintains the position of thestop, but provides breakaway capability for the stop in the event ofmisalignment of the precision conveyor. The breakaway prevents anydamage to the conveyor boat 40 from the hard stop 80 in the event of anymalfunction of the device. The pivot arm 150 is pivoted about pivotpoint 153 by means of a guide roller 154 and a face cam 155 which isrotated by the Camco drive motor 42 through belt assembly 157.

The face cam 155 is illustrated in FIG. 12 and provides for reciprocalmovement of the hard stop mechanism of approximately 1/8 of an inchduring each dwell period. The cam surface is illustrated with A-A' beingthe reciprocal distance, dwell period B, being the retracted dwellperiod, dwell period D being the engaged dwell period, and C being oneof the transition periods. The pivot arm 150 is pulled into engagementwith the face cam by means of a tension spring 158. As the face cam 155is rotated, the hard stop is held in its engagement position forapproximately 195° of rotation of the face cam and held in its retractedposition for approximately 120° of travel with transition periodstherebetween. The ratios of belt drive mechanism 157 are chosen toprovide one cycle of rotation for the face cam 155 for each step advanceof the conveyor boat 40.

Multi-Axis Gripper

The multi-axis gripper 18 used by the present invention is described indetail in U.S. Pat. No. 5,473,810, and receives the needle from theprecision conveyor and moveable hard stop mechanism, and transports theneedle through the swage operation in which a suture is automaticallyinserted into the barrel end of the needle, and the metal of the needleswaged about the suture. As can be appreciated, when the opening in thebarrel is only 0.0106 and the suture diameter is 0.0088, a high degreeof precision handling is required, particularly so when the insertionand swage operation need to be completed in approximately 0.5 seconds inorder to maintain a 60 needle per minute cycle rate. The multi-axisgripper also transports the needle through the pull test station inwhich the suture bond is tested and to the packaging area, where thearmed suture (needle and suture) is either bundled for future packaging,or mounted in an RSO tray such as the trays illustrated in FIGS. 2(a)and 2(b).

As illustrated in FIG. 14, the gripper portion of the multi-axis gripperis illustrated, with three needle gripping pins 156,157,158, that extendoutward from the gripper to engage a portion of the needle 19 therein.Pins 157 and 158 are fixed and pin 156 is reciprocable along channel 162to grip the needle 19 in a three point gripping engagement. The moveablehard stop 80 provides a precise positioning point for the butt end ofthe needle 19, and the pins 157, 158 of the multi-axis gripper provideprecise arcuate placement for the needle.

In operation, a plurality of multi-axis grippers are employed, each ofwhich grips a single needle for swaging, testing and packaging.Referring to FIGS. 5, 11(a) and 15(a), as the multi-axis gripper ismoved into position, the pin 156 is opened and the gripper isreciprocated towards the needle so that open pins are presented on eachside of the needle. The jaws 47,49 of the precision conveyor boat arethen opened, and during transfer, the needle rests on the moveable hardstop 80. Pin 156 of the multi-axis gripper is then closed to grip theneedle and the moveable hard stop is reciprocated out of engagement withthe needle, and away from the jaws 47,49 of the precision conveyor toallow the precision conveyor to advance the next needle into the needletransfer position.

While the invention has been particularly shown and described withrespect to the preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formand details may be made therein without departing from the spirit andscope of the invention, which should be limited only by the scope of theappended claims.

What is claimed:
 1. An automatic needle sorting and infeed apparatus forsingulating and precisely positioning curved surgical needles forsubsequent swaging, said apparatus comprising:(a) means for individuallysingulating a single needle from a bulk supply and depositing a singleneedle upon a first conveyor means; (b) means for obtaining an image ofsaid needles at one or more predetermined locations upon said firstconveyor means, said means including digitizing means for convertingsaid image into digital signals; (c) computer control means forprocessing said digital signals to obtain positional and orientationdata for each selected one of the imaged needles on said first conveyormeans; and (d) transfer means for removing said needle from said firstconveyor means in accordance with its individual positional andorientation data and transferring said needle to a second precisionconveyor for further orientation and precise position; (e) a precisiontransfer station for transferring the needle to a multi-axis gripper fora subsequent swaging operation.
 2. The automatic needle sorting andinfeed apparatus as claimed in claim 1 wherein said transfer meansincludes one or more robot means each robot means having a gripper meansfor picking up needles from said first conveyor means, and placing saidneedles upon said second conveyance means.
 3. The automatic needlesorting and infeed apparatus as claimed in claim 1 wherein said secondprecision conveyor means includes one or more engagement devices forgripping a respective needle, said transfer means placing each saidneedle in a respective engagement device.
 4. The automatic needlesorting and infeed apparatus as claimed in claim 1 wherein said computercontrol means further includes memory means for storing said positionaland orientation data corresponding to said imaged needles, said transfermeans including means for accessing said memory means to obtain saidpositional and orientation data corresponding to said imaged needles. 5.The automatic needle sorting and infeed apparatus as claimed in claim 1wherein said means for obtaining an image of said individually depositedneedles includes one or more camera means, each of said one or morecamera means in communication with said computer control means.
 6. Theautomatic needle sorting and infeed apparatus as claimed in claim 5wherein each of said camera means obtains a video image of said needlesupon said first conveyor means at each of respective said one or morepredetermined locations within a field-of-view of each of said one ormore camera means.
 7. The automatic needle sorting and infeed apparatusas claimed in claim 4 wherein said robot means is in communication withsaid memory means, said robot means accessing said memory means toobtain said positional and orientation data corresponding to said imagedneedles.
 8. The automatic needle sorting and infeed apparatus as claimedin claim 3 wherein each of said engagement devices includes a pair ofengaging jaws for engaging a needle positioned therebetween by saidtransfer means.
 9. The automatic needle sorting and infeed apparatus asclaimed in claim 8 wherein each said engagement device further aincludes spring means for biasing a first movable jaw of said pair ofengaging jaws into engagement with a second fixed jaw of said pair ofengaging jaws to retain said needle positioned therebetween.
 10. Theautomatic needle sorting and infeed apparatus as claimed in claim 9wherein each of said engagement devices further includes means forretracting said first movable engaging jaw from engagement with saidsecond fixed jaw prior to positioning said needle therebetween.
 11. Theautomatic needle sorting and infeed apparatus as claimed in claim 10wherein said means for retracting said first movable jaw from engagementwith said second fixed jaw is a push rod for pushing said first movablejaw in opposition to said bias of said spring means.
 12. The automaticneedle sorting and infeed apparatus as claimed in claim 3 furtherincluding a first orienting means for orienting each said needle in auniform direction while positioned upon said precision conveyor means.13. The automatic needle sorting and infeed apparatus as claimed inclaim 12 further including a second orienting means for furtherorienting said needle axially within said pair of engagement jaws. 14.The automatic needle sorting and infeed apparatus as claimed in claim 13further including a third orienting means for further orienting saidneedle to within 0.001 inch of a desired predetermined orientation forsaid needle upon said second conveyance means.
 15. A method forautomatically sorting needles comprising the steps of:(a) singulating asingle needle from a bulk supply of needles and depositing individualneedles in a spaced relationship upon a first conveyor means; (b)obtaining an image of said deposited needles upon said first conveyormeans and digitizing said image; (c) processing said digitized image toobtain positional and orientation data for one or more of said depositedneedles; (d) transferring said selected needle from said first conveyormeans to a second precision conveyance means in a predeterminedorientation based upon said positional and orientation data; (e)precisely positioning said selected needle for transfer to a multi-axisgripper for subsequent automatic swaging.
 16. A method according toclaim 15 wherein the step (c) of obtaining positional and orientationdata for a selected deposited needle further includes the step ofprocessing said positional and orientation data for generatinginstructions to enable a robot arm means to grasp said selected needleat a preselected location in accordance with its respective positionaland orientation data and transfer it to said second conveyance means ina predetermined orientation.
 17. A method according to claim 16 whereinthe step (d) of transferring the needles further includes the step ofplacing each needle between a pair of engagement jaws located upon saidsecond precision conveyance means.
 18. A method according to claim 17further including the step of pre-positioning said needle while carriedby said pair of engagement jaws on said second precision conveyancemeans.
 19. A method according to claim 18 further including the stepreorienting said needle from a horizontal orientation to a verticalorientation, and then releasing said pair of engagement jaws to restsaid needle on a moveable hard stop for transfer to a multi-axisgripper.